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<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script type="text/javascript">
		var str='gf5dg435fgdgdg234kjhhk24h32k4h2';
		//var re=/\d+/g;
		var re=/[a-z]/g;
        // \d 代表数字
        // + 多少都可以
        // g 全局匹配
        
		alert(str.replace(re,'0'));
	</script>
</head>
<body>
	
</body>
</html>